Francesco Redi

Redi placed meat in three flasks -- one open, one sealed and one covered with gauze. Maggots appeared in the open flask, as the flies were able to reach the meat. Maggots did not appear in the sealed flask or the flask covered by gauze. At the time, this experiment was not thought to disprove Spontaneous Generation. It merely proved that maggots did not come from meat. [1]